The present invention relates generally to clutch release bearings, particularly for automobile vehicles.
As is known, clutch release bearings of this kind generally comprise an operating element intended to be subjected to the action of a movement control means, which in practice is a clutch release fork, and a driving element intended to act, through the action of the operating element, on the release device of the clutch with which it is associated.
The present invention relates more particularly to the guiding of a clutch release bearing during its movement.
This guiding is generally effected by one or other of two separate methods.
According to the first of these methods, which is now rarely used except for so-called graphited clutch release bearings which do not incorporate ball bearings, the clutch release bearing is carried by the release fork with which it is associated.
This arrangement has the disadvantage that during its movement the clutch release bearing follows a circular and not a rectilinear path.
According to the second method of guidance, which at the present time is the one most usually employed, particularly for clutch release bearings having a ball bearing interposed between the operating and driving elements, the clutch release bearing is mounted for axial sliding on a guide member, for example a tube or sleeve with which it is coaxial, and the operating element is provided in its central zone with a guide passage adapted to permit its engagement on the guide member.
This arrangement has the advantage of permitting rectilinear guiding of the clutch release bearing along the actual axis of the clutch release device on which it is to act.
However, this method on the one hand entails the utilisation of a guide member which may be difficult to install and which may be expensive to produce, particularly when minimum longitudinal dimensions have to be achieved, while on the other hand in order to facilitate the sliding of the clutch release bearing on the guide member, it is also necessary to provide its operating element with a sleeve, the thickness of which cannot fail to increase correspondingly the radial dimensions of the clutch release bearing.
The general object of the present invention is to provide an arrangement which avoids these disadvantages, while achieving accurate rectilinear guiding of the clutch release bearing in question.